Gene Bolster was an aerospace engineer in Southern California when he got the call to take over his parents' farm in the Sierra foothills outside of Placerville. They had purchased the land in Camino five years earlier as a retirement project, but then his father died of a heart attack and his mother wanted to sell.

Surrounded by pine trees, an apple orchard stretching up a hill with views of the Sierra to the east, what's now called Bolster's Hilltop Ranch was impossible to resist. So in 1956 Gene Bolster moved his young family north to oversee the farm while continuing his career at nearby Aerojet as part of the team that helped NASA to put a man on the moon. Meanwhile, he played a crucial role in turning the area into what is known as Apple Hill.

Now a group of more than 50 apple growers, bakeries, wineries and Christmas tree farms located north of Highway 50, Apple Hill attracts some 700,000 visitors annually. It will celebrate its 50th anniversary this summer and fall, its main growing season.

But half a century ago, things were different. The area was dominated by pear orchards suffering from a disease called pear decline.

"The writing was on the wall. The industry was dying," says Gene Bolster's son, David, who now runs Bolster's Hilltop Ranch.

In 1964, Gene Bolster and county agricultural commissioner Ed Delfino visited the Southern California farming community of Oak Glen, where farmers had created a tourist destination around their apples, opening their farms to visitors with farm stands and baked goods. This was long before the modern farmers' market movement, and the vast majority of farmers sold wholesale rather than directly to consumers.

"Oak Glen basically had all the same ingredients we do - a good growing region in proximity to a large metropolitan region," says David Bolster. Also, the area is at a good elevation for growing apples, if at the high end. Bolster's, for example is at 3,200 feet, which means cold nights in winter that develop the fruit's flavor.

Gene Bolster and Delfino brought home 8mm film they took of Oak Glen to show local farmers. About 16 of them agreed to pull out their dying pear trees to plant apples.

Larsen Apple Barn, run by a family that had been farming in the area since the 1860s, opened a bakeshop, and others followed. As more visitors came, farmers offered U-pick apples, berries and Christmas trees, and others opened wineries and tasting rooms.

Bolster family history repeated itself in the early 1980s when Gene Bolster was ready to retire and announced that he would sell the land unless one of his children took over.

"I'm the only fool that had an interest in farming. I helped my dad run the farm until he passed away" in 2004, says David, who lives on the property with his wife, Miriam, and also works as a real estate agent.

Bolster's Hilltop Ranch opens in early June for U-pick blueberries, then again in late summer through early November for U-pick apples, apple cider and baked goods.

Bolster attributes the public's newfound interest in farming to boosting the numbers of U-pick visitors.

"It used to be a sidelight," he says. "Apple Hill has been both a leader and a beneficiary of the whole locavore and farm-to-table movement."

If you go

Bolster's Hilltop Ranch: 2000 Larsen Drive, Camino; (530) 644-2230. Open early June to July, then Labor Day to Nov. 10. For more on 50th anniversary events, see www.applehill.com.